The microelectronic and semiconductor industries often use starting material, such as silicon crystal ingots, in manufacturing various devices. Applications of this starting material, such as micromachined devices, sometimes require wafers having special crystal orientations, such as {110} (a "{110} wafer").
Fabrication of starting material having a special orientation typically requires low oxygen concentration material because of etch artifacts. These etch artifacts can be caused by agglomerations of oxygen in the crystalline material and are detrimental to producing the desired orientation. This problem is described further by D. L. Kendall and R. A. Shoultz in "Handbook of Microlithography, Micromachining, and Microfabrication", Vol. II: Micromachining and Microfabrication SPIE Press, September 1997.
Low oxygen concentration in silicon can be achieved by float-zone ("FZ") growth. However, FZ &lt;110&gt; ingots from which {110} wafers can be cut are not readily available in the current market. Furthermore, cutting &lt;100&gt; or &lt;111&gt; ingots using a conventional technique to form {110} wafers is inefficient.